The University of Puerto Rico Clinical Trials Unit (UPR-CTU) is a coalition/merge of the three previous independent Clinical Trials Sites associated to the AACTG, HVTN and PACTG Networks. The newly formed UPR-CTU will continue to have 3 Clinical Research Sites which will work with the Leadership Networks established to further advance the high priority areas related to: Vaccine Research and Development, Translational Research/Drug Development, Optimization of Clinical management, including Co-Morbidities and Prevention of Mother to Child Transmission of HIV. Letters confirming our affiliation to the following Networks are included in section h. (Consortium and Contractual Agreements): AIDS Clinical trials Group (ACTG), International Maternal Pediatric Adolescent AIDS Clinical Trials (IMPAACT) and the HIV Vaccine Trials Network (HVTN). The Goals of the UPR-CTU are to integrate three previously independent clinical research units into a single complex but operationally efficient Clinical Trials Unit. Improved efficiency and expansion of services will be the result of the integration/merge of specific units or functions within units. For example: a centralized pharmacy with better infrastructure will be able to provide quality services and expanded functions. Cost containment is expected since mayor infrastructure investments will be localized to a central site. Community interaction including community education and recruitment will also be integrated or merged in order to maximize resources and outcomes. The UPR-CTU already has a centralized laboratory which has provided services and support to the three previously independent units. The scientific input and expertise of the Laboratory Director will be incorporated into the Executive Committee composed of the co-investigators. The UPR-CTU has the access and capacity to recruit the following populations: men and women living with HIV (mostly Hispanic minorities) either treatment naive or experienced, pregnant women living with HIV, infants born to women living with HIV, infants, children and adolescents exposed to HIV or infected with HIV, Low (behavioral) risk HIV negative volunteers (men and women), High risk heterosexual women (commercial sex workers, crack/drug users, sex partners of IDUs) and High risk MSM. Not only operational efficiency is expected but also, future research collaborations within networks will be simplified at the units. The expertise for vaccine trials, adolescent medicine, special populations, women (pregnant and non-pregnant) and minority issues just to mention a few, can be shared between the clinical research sites.